\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usepackage{wasysym}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes,}
\begin{document}
\small
\begin{tikzpicture}[>=stealth,scale=1]
  \fill [pattern=north east lines] (-3.2,-.5) rectangle (-3, .5);
  \draw (-3,-.5)node[below]{$M$}--(-3,.5);
  \draw (0,-2)--(0,2);
  \draw[->](2,0)--(1,0);
  \foreach \x in {-2,-1.8,...,2}
  {
      \draw (0,\x)--(.1,\x);
  }
  \draw (-3,0)--(2,0)node[right]{\sun};
  \node at (2.75,0){$S$};
  \node at (0,0.2) [right] {$O$};
  \draw (-3,0)--(0,1);
  \draw[dashed, very thick] (-3+.15,-.5)--(-3-.15,.5);
  \node at (0.2, 1.75){$n$};
  \draw [very thick] (1.5, .5)--(1.5, .1);
  \draw [very thick] (1.5, -.5)--(1.5, -.1);
  \node at (-1.5,-.2){$\ell$};
  \draw [<-](-1.5,0)--(0,0);
  \draw [<-](-1.5,0.5)--(-3,0);
\end{tikzpicture}
\end{document}